Vascular catheters having extension tubes joined to their proximal ends are known, with catheters conventionally being made of either silicone or polyurethane while the extension tubes are polyurethane or polymers other than silicone. One manner of connecting an extension tube to a catheter lumen is to provide complementary luer fittings on both the proximal catheter end and the distal tube end, for removable connections. Another manner of connection, especially for use on multi-lumen catheters, is to provide a hub component that is affixed to the proximal end of the catheter and to the distal ends of one or more extension tubes associated with respective lumens of the catheter; the hub provides a channel or passageway establishing fluid communication between each extension tube and a respective lumen of the catheter, defining a catheter assembly. Commonly, the hub is insert molded of polyurethane onto the respective catheter and extension tube ends with the use of mandrels that define the channels of the hub during molding. Use of such assemblies is well known for hemodialysis and for infusion of medication into or drawing of blood from a patient, or both.
Molding of a hub onto a proximal end of a multi-lumen catheter simultaneously with molding it onto the distal ends of a plurality of extension tubes associated with the catheter lumens, is known. One such molding process is disclosed in U.S. Patent Publication No. 2005/0080398, which disclosure is incorporated hereinto by reference, including the use of mandrels extending from within the extension tube passageways and into the associated lumens of the catheter at the proximal ends thereof. The mandrel portions extending between the extension tube distal ends and the catheter proximal end define passageways through the hub body formed within a hub mold to surround end portions of the extension tubes and the catheter and seal with outer surfaces thereof, which hub passageways define fluid communication between the extension tube passageways and the respective lumens.
It is desired to provide a manner of connecting a catheter lumen to a respective extension tube where the extension tube may be made at least partly of silicone.